Everything Mac Posted March 19, 2014 Share Posted March 19, 2014 One, that this new coke I've got is liable to spit. I got hit in the face with a lump of it shooting out if the fire. What causes this then? Moisture in the coke? Air? Two, that the tuyere I've used in my forge for the last year or so on charcoal without so much as a scratch, has lasted two days with the coke. It was covered on clinker after the first burn so I cleaned it off and started again today. Now it looks like this.... Needless to say that this one is done. I'll build another in a couple of weeks when I get back home. Any ideas what caused this? Poor fire management I suspect. I'm so used to not getting clinker that I've never had to stop to clear it out. Any suggestions as to how to make the replacement? This one was 10mm plate welded to the pipe. I feel I may have to return to using charcoal... Cheers Quote Link to comment Share on other sites More sharing options...
the iron dwarf Posted March 19, 2014 Share Posted March 19, 2014 I have no problem with coke but I dont use steel, grade 250 cast is all I use and 18 to 20mm thick. out of well over 450 made no one has ever needed a replacement Quote Link to comment Share on other sites More sharing options...
basher Posted March 19, 2014 Share Posted March 19, 2014 if you are using a side blast forge powered with a blower and working for more than a short time between blast shutoffs. you will quite happily melt steel and cast iron tue unless they are water cooled. My Cast iron tue from vaughns lasted less than 2 hours. its just simple maths, throw more heat at the steel than it can happily conduct away and it will melt. Although coke apparently has a lower burn temp than charcoal.... this does not translate to a forge environment. Quote Link to comment Share on other sites More sharing options...
the iron dwarf Posted March 19, 2014 Share Posted March 19, 2014 one reason I only make bottom blast, come and take a look at the IBF, I will bring along the oldest and most used tue I have ( the central one of five in our big forge ) Quote Link to comment Share on other sites More sharing options...
Everything Mac Posted March 19, 2014 Author Share Posted March 19, 2014 This is a bottom blast, and from conversations over on Facebook it seems a few factors have contributed to its demise. Namely being raised up above the bottom of the pot, with a slight gap around it so that any coke around the base is being fueled by the air supply. I reckon it had a wee furnace right next to it. I'll rebuild it all when I get back home in a couple of weeks. In all honesty I can see me building a water cooled side blast forge in the near future. Cheers Andy typo corrected: side draft applies to the exhaust flue, not the tuyere Quote Link to comment Share on other sites More sharing options...
dablacksmith Posted March 19, 2014 Share Posted March 19, 2014 ya if the grate is raised above bottom of forge it can burn out any grate ... gota make the grate the low place on the forge ... also what did you make the grate from? how big an opening ? coke burns hot so might go with a thicker grate ... last one i made was out of 1/2 round rod with about 1/4 in gap between ...good luck! Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted March 20, 2014 Share Posted March 20, 2014 The piece that popped and hit you was probably steam driven from internal moisture. I usually start the fire with coal then feed from the side with coke so it gets warm enough to drive off the moisture prior to actually landing in the fire. Quote Link to comment Share on other sites More sharing options...
Joel OF Posted March 21, 2014 Share Posted March 21, 2014 Coke spits when there's moisture in it, to stop it spitting dry it out on the outside of the forge before raking it in to the middle. Once I was hit on the bridge of my nose so hard by a piece of spitting coke that it cut me. WEAR EYE PROTECTION. Quote Link to comment Share on other sites More sharing options...
Everything Mac Posted March 28, 2014 Author Share Posted March 28, 2014 Yeah I thought I'd managed to dry it out plenty but obviously not enough. Never mind. I'm very proactive when it comes to my ppe these days. I always wear ear defenders and eye protection. Cheers Andy Quote Link to comment Share on other sites More sharing options...
BackyardBlacksmithin Posted April 20, 2014 Share Posted April 20, 2014 I just had the same issue with coke popping at me this week as well... My first time using purchased coke, I normally use just coal. Had a few pieces pop real good and actually bounced off my safety glasses. I will have to do like the other guys mentioned and just slowly introduce the coke from the side of the fire. And I noticed as well that it took quite a bit more air to get it to the same temp. I think I might just save the coke for when I'm doing forge welding, much easier to maintain a very clean fire with coke. Quote Link to comment Share on other sites More sharing options...
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